kernel: expose umount list to ioctl interface (#2950)

This idea is borrowed from simonpunk's susfs4ksu.
What we see here is that, yeah well, lets just have userspace send us
what it
wants unmounted, this is better than hardcoding everything.

This also solves that issue where MNT_DETACH fails, as long as we send
unmountables in proper order.

A small anti-duplicate mechanism is also added.

While in-kernel umount is a bit worse than zygisk-provider-based ones,
this can still
serve as a healthy alternative.

---------

- Remove duplicate checks

Signed-off-by: backslashxx <118538522+backslashxx@users.noreply.github.com>
Co-authored-by: weishu <twsxtd@gmail.com>
Co-authored-by: ShirkNeko <109797057+ShirkNeko@users.noreply.github.com>

manager/app/src/main/res/values-es/strings.xml

@@ -124,7 +124,6 @@
     <string name="selected_lkm">LKM seleccionado: %s</string>
     <string name="save_log">Guardar registros</string>
     <string name="log_saved">Registro guardado</string>
-    <string name="sus_su_mode">Modo SuS SU:</string>
     <!-- Module related -->
     <string name="module_install_confirm">¿confirmar la instalación del módulo %1$s?</string>
     <string name="unknown_module">módulo desconocido</string>
@@ -274,8 +273,6 @@
     <string name="advanced_settings">Configuraciones avanzadas</string>
     <string name="appearance_settings">Personalizar la barra de herramientas.</string>
     <string name="back">Retorno</string>
-    <string name="susfs_enabled">SuSFS activado</string>
-    <string name="susfs_disabled">SuSFS desactivado</string>
     <string name="background_set_success">Fondo establecido correctamente</string>
     <string name="background_removed">Eliminar fondo personalizado</string>
     <string name="icon_switch_title">Icono alternativo</string>